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I retightened crank bolt, still supposed to have clutch noise?

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Its a 2002 ktm400exc.

After finding my two stator bolts loose and floating in my flywheel :lol: i decided I better check the crank nut on the clutch side. It was loose. I re tightened it to 110 ftlbs, red locktited. My clutch is still weird sounding when not pulled in while in nuetral. When I pull in the clutch in it gets quiter. It s always been that way but I thought I found the answere, guess not.

Did those of you who fixed your crank nuts find that the weird ktm clutch noise went away? Was it supposed to? I did not put a new woodruf key in so maybe that is still why? ( Local ktm did not have one and i needed it finished since my days off were ending and it was apart in the basement).

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I think I may have found my answere in the following post from a 2009 thread......

#3 02-23-2009, 10:35 PM

DRZnXJnWI

TT Gold Member

My Garage Join Date: Jan 2005

Location: Wisconsin

Posts: 1,372

your talking about the crank nut- its not connected to the clutch as you suspected- its "the crank nut" the clutch is mentioned because the full repair requires removal of the clutch. But you can check and retighten it without replacing the woodruff key (need to take the clutch off to pull the free wheel off- to get to the woodruff key)- Just better to do the replace it for the long run. $.50 and sounds harder than it is.

In your case- if the noise you hear is on and off with the clutch exclusively- nothing else- in that case- its normal. Seems I remember a ktm guru stating something about oscillation and harmonics yadayda- but for you and me if its normal its normal- ok.

If you start hearing a whirling type noise- your description sounds close if its while riding it- its the crank nut in many cases, very common on rfs- yet not all cases- if it is left it can sound more evasive and concerning- like its going to rattle into bits- someone once ignored it and the nut wore through the side cover- but it could cause other wear- woodruff keys shear- bad, slop on crank bearing can't be good-

many good threads on that topic here-

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First these RFS are noisey...steel clutch basket resonates like a tunning fork amplifying sounds...pull in the clutch and it shud quite dow...also skid plates(especally aluminium) reflect a lot of noise. :cheers:

I've had my 06 for two years now and the "noise" still bugs me a bit but it hasn't skipped a beat...pull in the clutch and most of it goes away :lol:

That being said the early RFS's are known to potentally have potential problems with loose primary nuts...also know as the crank nut.

Here is some info I have copied from the KTMTalk site concerning primary nut that may be helpful. There's a lot of gud info over there. :):thumbsup:

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Right side coming loose?

KevInYorks: http://ktmtalk.com/index.php?showtopic=413...dpost&p=3594454

A quick check - put the bike in gear, with the front wheel against a wall, gently release the clutch, enough to load up the transmission but not enough to stall it.. If it goes quiet it is likely to be the crank nut.

KevInYorks: http://ktmtalk.com/index.php?showtopic=401...dpost&p=3460496

New woodruff key; Clean shaft and inside gear with carb cleaner; Smear shaft with green loctite (high strength retainer); Put gear on shaft; Red loctite on threads; Tighten nut to 150 Nm. Will never come loose again :smirk:

DJH: http://ktmtalk.com/index.php?showtopic=401...dpost&p=3460604

What Kevin said! Loctite on the threads is nice, on the shaft is critical! Also critical that you not get it in the sprag clutch and needle bearings that are further in.

KevInYorks, from: http://www.ktmforum.co.uk/technical-how-to...ath-rattle.html

Here's one I did earlier Checking crank nut

Parts: clutch cover gasket, clutch locking washer, primary gear key, primary gear nut.

• Lay bike on it's left side.

• Remove kickstart and brake lever.

• Remove clutch cover, note the two longer screws go where the dowels are.

• Put a penny in between clutch and primary gear teeth

• Undo primary gear nut – left hand thread

• If the nut came off without too much effort it was loose. If it took some swinging to get it off it was not loose, so clean up the threads, red loctite and torque it up to 150Nm then put the cover back on. If it was loose, carry on………

• Remove 6 allen screws from clutch a bit at a time, set bolts, washers and springs aside

• Remove cover plate – watch out for a plain plate stuck to it underneath

• Remove throwout bearing assembly from middle, look out for rod stuck to it

• Remove clutch plates

• Remove steel tubes from hub

• Knock down tabs on lock washer

• Hold clutch and undo nut***

• Remove hub - watch out for a stepped washer sitting in the hub

• Remove two half washers

• Remove basket - watch out for two needle roller bearings and a washer under them sitting on the shaft

• Remove circlip and washer off oil pump drive and pull off gear, remove drive pin

• Pull off primary gear

• If the primary gear came off without a puller it is worn inside, needs to be fitted with green loctite to stop it moving. Also needs a new woodruff key as I bet it is marked/stepped if you take it out.

• Clean the crank thoroughly with carb cleaner, the plain bit and the threads.

• Clean the nut and the bore of the primary gear.

• Clean the clutch nut and shaft threads.

• Put some green loctite (high strength retainer) on the inside of the primary gear (not on the freewheel bearing) if it is anything but a tight sliding fit.

• Put some red or green loctite on the nut threads.

• Put it back together quickly, put the oil pump drive gear back on, put clutch basket and bearings/washer on quickly and torque the crank nut to 150 Nm by locking the gear with a penny.

• Wipe off the excess loctite from the nut.

• Rebuild rest of clutch

• Put red loctite on clutch nut threads and tighten to 90 Nm then squeeze the locking tab back into place.

• ***if you dont have a clutch holder drill through 2 plain and 2 friction plates and bolt together fit those 4 plates in clutch lock clutch to primary gear by inserting a penny between gears

• Note: 02 and earlier models do not have the clutch locking washer, nut or stepped washer as the clutch is held on by a circlip. You will need a good pair if external circlip pliers to remove it.

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:banghead:

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mine makes noise too. I have seen several videos of what it isn't supposed to sound like, but none of what it is supposed to sound like. has anyone done a before/after video of the crank bolt tightening? I can't decide if mine needs tightened and I have no experience with them to know. When I pull in the clutch it doesn't go away, and when I put the front wheel against a wall and put it in gear, let out the clutch to load it up, it still doesn't go away. Makes me think maybe it is normal, but again... I dont know???:lol:

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Cool thanks for info. But rod d I would check that crank nut. Mine was loose. I didn't notice any differance in noise once tightened though. It only takes like a half hour to check.

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My noisy clutch had an easy fix - ear plugs. Now it never bothers me.

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My noisy clutch had an easy fix - ear plugs. Now it never bothers me.

LOL! I need to try that to. The noise always bugs me when I first start out for a ride but then I guess I get used to it after a while. Them RFS motors sound like they are coming apart half the time but nothing ever happens, they just keep chuggin along. I notice it the most if I'm at a steady rpm without much load on the engine. They sound great when you twist the throttle though! :lol:

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Cool thanks for info. But rod d I would check that crank nut. Mine was loose. I didn't notice any differance in noise once tightened though. It only takes like a half hour to check.

Yeah I think I will. One question that I can't seem to find the answer to is, do I have to drain the oil to check it? I read somewhere to lay it on the left side so the oil won't run out of it, but I don't know if that means the oil that is left after draining it, or if the oil level will really be low enough without draining it? Seems possible since the sight glass is pretty low on the case and the oil level is not really that high, but I don't know. Thanks!

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No need to drain the oil. Just lay the bike on its side and you will be fine

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Cool, thanks. I checked it and sure enough it was a little loose. I didn't fully prepare by getting the new woodruff key, so I just cleaned the threads and used some red loctite for now. I haven't started it yet, will probably take a while for it to set up with the cold weather. I did look at the key and it appeared to be in good shape, at least from what I could see. I am hoping that this will take care of it, but I will get the key to be prepared for next time...

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